Under the optimital HPLC separation condition, a satisfactory separation of the purified anthocyanin extract of R. tomentosa was obtained and the HPLC chromatogram is shown in Fig. 3A.
The Major anthocyanins represented about 99% of the total peak area with regard to the UV–Vis spectrum taken on-line during HPLC and chromatographic features. However, other minor peaks were also detected which had percentage areas of less than 1%. No UV absorbance maxima in the 310–320 nm range were detected, indicating no acylation of anthocyanins with aromatic acids